PC Power Supply for DC Charger?

[pilot_bear]

no harm checking the fuse on the psu and plug.

use a volt meter to check the wire, the fan might be faulty ?

[teinsports]

no harm checking the fuse on the psu and plug.

use a volt meter to check the wire, the fan might be faulty ?

ok, will try agn tonight. thanks for all the inputs.

[teinsports]

Orite guys, update.

Shorted the green n black wires n tested with my charger. Powered on and same thing happened, juz a short blip n went dead.

Next, i removed the psu casing n tested the presence of current with a tester which detects current. Current is detected all the way from the power socket, power cable, transformer n the main red wires in the psu. No current detected from all the small coloured wires which starts to branch out from the psu(not from the outside of the psu).

Any other methods? Any electrical gurus who can help???

[teinsports]

Orite guys, update.

Shorted the green n black wires n tested with my charger. Powered on and same thing happened, juz a short blip n went dead.

Next, i removed the psu casing n tested the presence of current with a tester which detects current. Current is detected all the way from the power socket, power cable, transformer n the main red wires in the psu. No current detected from all the small coloured wires which starts to branch out from the psu(not from the outside of the psu).

Any other methods? Any electrical gurus who can help???

[pilot_bear]

safety feature ? cut off power if no "resistance" detected ?

if you have an old fan or old motor, try tapping on to the appropriate
voltage colour wire and black (example: if 5v fan, tap to the 5v wire).
the idea is to form a parallel circuit. then do a test on the small wire again.

[teinsports]

safety feature ? cut off power if no "resistance" detected ?

if you have an old fan or old motor, try tapping on to the appropriate
voltage colour wire and black (example: if 5v fan, tap to the 5v wire).
the idea is to form a parallel circuit. then do a test on the small wire again.

erm, but i tested it with my charger n it doesn't work as well...

[Nazar78]

Another alternative for 10omh 10watt

hi all,

this is an old thread, but since its sticky i juz wanna share;

when i did this psu for charger, i ran out of potentiometers, no specific 6v bulb or sandbar resistor 10omh 10watt (no time to shop). so i was lookin ard at home and thought of something;

resistors/potmeters are commonly made wit either mixture of ceramic or carbon compound. carbon used in resistors are able to withstand high working temps, normal 70deg up to 150deg if im not mistaken.

I have some small broken carbon parts (from crashed heli parts), took a few small piece, filed the edges to expose the inner carbon, test each resistance wit a dmm. the larger or more carbon stacked together, the more resistance it will have plus withstand heat. 2 piece small carbon plate (2x2cm*0.2cm) stacked together giving me abt 6omh, thats 12.6v reading on dmm. with larger carbon, should b able to reach 13.+v with no problem. Ive tried touching the carbon plates (no temp probe), something like hot scorpion motor, but no too hot to touch.

pros: withstand and less heat

cons: carbon is $$$ unless u crashed

[Nazar78]

updates, i use a larger carbon (from cracked vertical fin), but place the 2x red/black wire like 2 cm apart for lesser resistance. means lesser resistance=more load, also lesser heat as the heat spreads on the large surface. dmm shows 13v on the 12v rails. i dont need 13v, now reading is 12.85v...

[HotDogBun]

Guys,
I have read through the thread, but am not very sure what are the actual wires used.
Pls guide me on what I have missed out.

Short green (on/off) wire to any black(ground) wire.
Take any yellow(+12V) and connect to positive input of charger.
Take any black(ground) wire and connect to negative input of charger.

Can I cut off all the other yellows blacks etc wires and cover individual with shrink tube to avoid shorting?

I noticed there are mods with the LEDs and resistors, can to explain abit more in layman terms?

[HotDogBun]

Found some of the links mentioned.

http://web2.murraystate.edu/andy.batts/ps/powersupply.htm

It mentioned for the LED, a dropping resistor is required to prevent LED from being burnt out. What kinda and rating resistor is he referring to?

[Super-Hornet]

Nowadays ATX power supply is quite stable and it is around 12V (or 11.8V). It is more than enough for your charger...thus, u can actually do not required to do those "loading" method that mentioned above.

I never use those loading method on my charger/PSU and it is working fine.

Beside, doing loading may not be good because of the heat generated from the load. If u are not careful, the load/resistant/resistor might get too hot and catch fire. Not only that, u waste energy just to heat up the resistor.

SH

[HotDogBun]

SH, so you mean to say, your mod on your PSU is actually as below?

1. Clear off all wires less Yellow, Black & Green.
2. Connect Green to any Black wire.
3. Connect Yellow and Black wires to - and + of charger.

Also, for 3, how many yellow and black did you use to connect? My PSU states 20A for +12V. I am worried if I use single wire, the load may melt the wires.

[Super-Hornet]

I did not clear any wires at all. The reason is that... who know one day I might decided to buy a higher capacity PSU and then reuse that PSU on my older computer instead

Due to my PSU has an external On/Off switch behind it, I connect a wire and short the Green to Black (on the Motherboard connector).

Then detached the Yellow and Black wires on Rail #1 for Charger #1 (The Drive connector. Reason is that, it is much easier to detach the pins)
Then detached the Yellow and Black wires on Rail #2 for Charger #2. (The Drive connector. Reason is that, it is much easier to detach the pins)

If u worry the wire cannot handle the maximum current, then u take out another Yellow and Black wires on the same Rail (But different connector) and connect to the previous one in parallel. Remember that try not to connect Rail #1 to Rail #2 in parallel. We not sure whether the internal circuitry from both Rail can coexist together or not (can connect parallel or not).

SH

[HotDogBun]

Rail #1 and #2?
Great, I cut off all wires from their connects and they are now all in 3 bundles according to their colours....
Which means I'll have to use only 1 yellow for my charger... right?

[Super-Hornet]

So u just cut all your wires and your PSU has multiple Rail? (See the sticker on the PSU or the box)

If so, great! Now u don't know which wire is from which Rail.

If your PSU do have multiple rail, then see the Yellow wire. It may differentiate different rail by color. If not, them try to measure the Yellow wire by multimeter. Different rail might have slight different voltage o/p.

Their black wire are common to all, so u can share them.

SH